Individuals requiring ambulatory aids, such as crutches ideally should support most of their weight on a hand support, such as the crutch handle. Conventional crutches are designed with a handle that is secured by a single fastener, such as a bolt, that extends through the crutch handle and through apertures in opposing, vertical crutch supports. The handle is therefore aligned with the crutch support apertures and is perpendicular to the vertical axis of the crutch. This places the hand in an abnormal, non-physiologic, radially deviated position causing abnormal, non-physiologic, compressive loads directed ulnaward across the radiocarpal joint of the involved upper extremity. The stresses of weight bearing transferred to the upper extremity via the use of crutches subjects the ligaments, nerves, joints and osseous structures of the wrist and surrounding structures to various overuse syndromes. The signs and symptoms of these overuse syndromes includes pain, swelling, muscle strain, tendonitis, synovitis, and neuropathies such as carpal tunnel syndrome to name a few.
The prevalence of wrist symptoms is frequently increased in the subset of patients requiring the prolonged use of crutches, those with pre-existing wrist pathology, and in the obese population. It is not uncommon to develop additional overuse-type symptoms as a result of a painful wrist incurred by the use of crutches in their current design. Once the wrist and surrounding structures become painful, there is a tendency to transfer weight bearing from the wrists to the shoulders via the use of the shoulder support of the crutch. The spectrum of additional complaints may include those associated with simple skin irritation of the shoulder to that secondary to impingement syndrome of the shoulder. Shoulder bursitis, tendonitis, synovitis and occasionally compromised integrity of the rotator cuff may occur simply due to overloading of the shoulder joint which was not designed as a weight bearing joint. Chronic compression of the axilla by the crutch shoulder support bar may cause direct injury to the nerves of the axilla of the shoulder resulting in a neuropraxia presenting as “crutch paralysis”.
There is a need for a crutch grip that places the wrist in a comfortable, neutral position, by improving the length/tension relationship of the engaged muscles to allow for optimal performance and reduced potential for injury. Such a position would set the tone and foundation for better posture and alignment for those using crutches. Improved posture will not only decrease the potential for wrist pain but also for back and shoulder pain by keeping the whole upper extremity in proper alignment. Also, the improvement in posture will lead to improvements in confidence and efficiency in movement using the crutches.